Ammonia from poultry litter is a leading cause of respiratory disease and eye damage in commercial flocks. Effective ventilation is a fundamental welfare requirement in intensive poultry housing.
Ammonia management in poultry housing is a welfare priority because airway and eye damage from high concentrations causes genuine, measurable suffering across entire flocks simultaneously. Keratoconjunctivitis reduces vision, affecting a bird's ability to find feed and water and increasing social vulnerability. Chronic low-grade respiratory irritation reduces growth rates and immune function independently of formal disease challenge. The relationship between ammonia and bird welfare is well-understood: maintaining concentrations below 20 ppm through adequate ventilation, litter management, and stocking density control is achievable in well-designed and managed houses. The challenge is economic — additional ventilation costs energy, and high stocking densities that produce ammonia problems also maximise short-term throughput. Regulatory minimum ventilation requirements and welfare audits that include ammonia measurement at bird level (rather than entrance height) are essential for meaningful welfare protection. Birds cannot leave high-ammonia environments — producer management is the only mechanism for welfare improvement.